748 SUMMARY OF CURRENT RESEARCHES RELATING TO 



isolated 17 different froms which he has found in or on the vats, in the 

 building, or even in the air. He describes the appearance of these, in 

 none of which has he detected any approach to spore-formation, thus 

 separating them conclusively from Saccharomyces. He gives the results of 

 his experiments to test the influence of these foreign organisms on the 

 process of brewing. At low temperatures their growth is much retarded. 

 A quite considerable effect on the taste and odour of the wort was pro- 

 duced by the presence of one or another of the organisms ; a slight de- 

 coloration was also noticeable. No influence on the acidity of the wort 

 was detected. Other tests were tried, and the final conclusion come to 

 was that no injury to brewing need be feared from the accidental 

 presence of these fungi, as with the increase of the true yeast their growth 

 and development are retarded or altogether stopped. 



Cucumber Leaf Disease.* — A new disease of the cucumber plant 

 has made its appearance quite recently. It is due to a mould Deadry- 

 phium comosum, hitherto known only as a saprophyte. The fungus 

 mycelium penetrates the tissue of the leaves and destroys it, in smaller 

 or larger areas. In bad cases the young shoots and fruits are utterly 

 ruined by the fungus. Advice is given as to prevention and cure. 



New Disease of Asclepias curassavica.j — G. Scalia describes a 

 new parasitic genus Oidiopsis which does serious damage to the plants 

 of Asclepias. The fungus lives in the tissue of the plant. The sparsely 

 branched conidiophores pass out through the stomata and bear chains of 

 colourless conidia. It resembles Oidiim, but differs from that fungus 

 in its endophytic character. 



Rhizoctonia violacea.J — This fungus, a sterile mycelium, causes a 

 root-disease of various plants. Jakob Eriksson records its appearance 

 at the Swedish Experimental Station, where it attacked a field of carrots. 

 A large number of experiments was made with a view to testing the 

 capability of the fungus to transfer itself from one host to another. On 

 diseased soil were planted several varieties of carrots and beets, clover, 

 lucerne and potatoes, of which some were attacked while others escaped 

 the disease. A tub of strongly infected soil was left standing and there 

 grew in it a series of weeds, Sonehus, Myosotis, Urtica, Stettaria, &c. 

 On the roots of all of them the fungus was found to be growing more 

 or less vigorously. The writer is of the opinion that the fungus does 

 exercise some choice as to its host and that it will take several genera- 

 tions to accustom it to a new plant. He tested and proved this theory 

 on sugar-beets. The attack of the fungus infected from carrot was 

 already much stronger in the second generation. Experiments were 

 made with the view to killing the fungus. Lime was added and 

 carbolic acid ; the results are unsatisfactory so far. 



A severe attack of the same fungus on sugar-beets is recorded by 

 Fr. Bubak.§ He blames the heavy and wet condition of the soil for 



* Journ. Board of Agric, x. (1903) pp. 16G-70 (1 pi.). 



t Agricolt. Calabro-Siculo, xxvii. (1903) No. 24. See also Centralbl. Bakt., x. 

 (1903) pp. 71-2. % Centralbl. Bakt., x. (1903) pp. 721-38 (3 figs.). 



§ Zeifschr. Zuokerind. in Bohraen, xxvii. (1903) p. 471. See also Centralbl. 

 Bakt., x. (1903) p. 747. 



